Typically in a graphics display system, it is desirable to be able to display the images to different types of displays. Conventional graphic display systems do allow displaying to a different display, but only if the timing is exactly the same for the displays. For example, in a conventional graphics display system, if a flat panel provides a 1600×1200×60 Hz scale image, a cathode ray tube (CRT) will display the same scale image. Typically this is accomplished utilizing a single head design which works for one display pipeline. To describe this single head design in more detail, refer now to FIG. 1.
FIG. 1 is a block diagram of a conventional graphics display system 10. The conventional graphics display system 10 includes a memory 12 which is in communication with a frame buffer interface 14. The system 10 includes a host 16 which receives programming signals from an AGP (or PCI) bus 18 which controls both a VGA controller 20 and a CRT controller 22. The VGA controller 20 retrieves information from and provides information to the frame buffer interface and communicates with the CRT controller 22 via register signals. The CRT controller 22 is coupled to pipeline 24. The VGA controller 20, CRT controller 22 and pipeline 24 comprise a single display head 40. In this single head system 10, the CRT controller 22 then provides data through a pipeline 24 to a plurality of displays, for example a CRT 26, flat panel (FP) display 28 or a television 30. Each of the displays can be serially switched onto the single head graphics system 10 or all of the displays can simultaneously receive the signals from the graphics system 10.
A problem with the single head system is that, unless all of the displays are compatible, then there are timing issues associated therewith. Accordingly, the pipeline would require complex circuitry to ensure that these timing issues are addressed, which would significantly add to the cost of the graphics display system. The conventional graphics display system 10 works well with traditional panels (800×600, 1024×768) which use standard VESA timings. However, the mobile industry is moving aggressively towards large flat panels (1600×1200, 2048×1536) with non-standard timings.
In addition, the higher resolutions are not supported by most CRTs. If multiple displays are to be utilized simultaneously they must be coupled tightly together. This is oftentimes undesirable because the costs associated with circuitry to allow for compatibility is prohibitive.
Accordingly, what is needed is a system that overcomes the above-identified problems. The present invention addresses such a need.